Only you being her friend will know what type of person she is, and whether or not she would take offence if you mentioned quite casually, that you were a bit uncomfortable with the smell, and vice versa if she understands you as a person then she would know it’s not coming from a bad place, but just a small favour if ever you were visiting her. I’m sure she would rather move the bowls into another room than lose a friend… so maybe keep things in perspective. It’s a bit like when some of my friends who don’t like dogs or are allergic to our dog… once they TELL ME then I will make sure he is either outside or out of sight, I definitely don’t take offence. If you specify it’s just the SMELL of the food, then that can be remedied by being put into another room whilst your there, that way your not offending her home, her cats, or her habits. Otherwise I’m in agreement with Grammy Grammy on this one, we all want our guests to be comfortable when they visit, but we can only accommodate their comfort if we know what pleases them.
The cat food smell isn’t her problem, its her way…. Whereas your problem is finding your way to tell her, I’m sure once you mention it she will think nothing more of it and you could save a small fortune on Vicks & Perfume ?